Ultrasonic swivel insert

ABSTRACT

An ultrasonic insert carries a rotary bearing adjacent to the transducer. The bearing slidably engages an ultrasonic handpiece. When seated in the handpiece, the insert is substantially decoupled, on a rotary axis, from the handpiece. A rotary force need only be applied to the insert to rotate it in the handpiece. Alternately, an adaptor can be inserted into the handpiece. The adaptor slidably receives a conventional ultrasonic insert. The conventional insert can be easily rotated with a force applied only thereto, relative to the handpiece.

This is a Utility Application claiming the benefit of the earlier filingdate of Provisional Application Ser. No. 60/223,447, filed Aug. 4, 2000and Ser. No. 60/270,687, filed Feb. 22, 2001.

FIELD OF THE INVENTION

The invention pertains to ultrasonic inserts of a type used inmedical/dental treatments. More particularly, the invention pertains tosuch inserts with enhanced operating efficiency and user comfort.

BACKGROUND OF THE INVENTION

Ultrasonic scalers are used in dental offices for de-plaqueing teeth.Unlike manual scalers, these instruments are powered i.e., the tip ofthe instrument vibrates at an ultrasonic frequency allowing quick andeasy debridement. The operator has less hand fatigue as most of theenergy for removing the plaque comes from the generator that powers theinstrument. The dental practitioner need only lightly touch the tip ofthe instrument at an angle to the tooth surface to dislodge the plaque.

Known ultrasonic scalers, such as scaler 10 illustrated in FIG. 1A, havea handpiece 12 a coupled at one end 12 a-1 to a cable 12 b whichincludes a hose, to provide a fluid, and conductors to provideelectrical energy. The other end of the cable 12 b terminates at anelectrical generator and fluid source 12 c. One type of fluid is water.

The other end of the handpiece 12 a-2 is hollow and is intended toreceive a replaceable insert 14 with a transducer 14 a (magnetostrictiveor piezoelectric) carried on the insert. The transducer 14 a extendsfrom a proximal end of the insert 14 into the hollow body 12 a-2. Anultrasonically vibrated tip 14 b extends from a distal end of theinsert. One such insert has been disclosed and claimed in U.S. Pat. No.5,775,901, entitled “Insert For Ultrasonic Scaler”, incorporated hereinby reference.

Known magnetostrictive ultrasonic inserts function by exciting a stackof thin nickel plates at a frequency equal to the stack's naturalfrequency. The excitation is induced through an electrical generator inunit 12 c, which supplies a current to a coil embedded in the handpiece.When the insert 14 is placed in the handpiece 12 a and the frequencygenerator 12 c is powered on, the operator tunes the generator (manualtuning) until it reaches the resonance frequency i.e., attains thenatural frequency of the insert. Alternately, auto-tune unitsautomatically lock on the insert resonance frequency once powered on. Atthis time, the stack starts vibrating. This vibration of the stack isamplified and transmitted to the tip 12 b by means of a connecting bodyor concentrator. The connecting body is made from material that providesgood sound transmission efficiency.

While the insert 14 is operational, fluid is pumped through thecable-generator system 12 b, c and through the handpiece 12 a to the tip14 b of the insert 14. The vibrating tip 14 b breaks the fluid streaminto a spray. The spray not only keeps the tip cool, but also keeps thesurface of the tooth cool and provides protection against tissue damage.

The fluid path through the handpiece 12 a needs to be sealed such thatno leakage occurs until the fluid stream exits from the insert at thevery tip through a fluid delivery channel. Typically, ultrasonic insertsdo not have any moving parts other than the minuscule displacement ofthe nickel stack, the connecting body or the tip.

Known magnetostrictive dental scaling ultrasonic inserts used in theU.S.A. are designed to vibrate at 25 kHz or 30 kHz frequencies. Anothersystem, popular in Europe, uses a piezoelectric transducer.

In using an ultrasonic scaler during a cleaning, the dental practitionerwill need to repeatedly re-orient the location of the insert tip 14 bwith respect to tooth surface depending on which tooth of the mouth isbeing cleaned. In making this angular adjustment, as illustrated in FIG.1B, the practitioner will typically take the insert out of the patient'smouth, rotate the insert 14, and tip 14 b, inside the handpiece 12 alocating tip 14 b at a desired angular position. Both hands are used forthis rotation as the frictional forces that produce a tight fit of theinsert 14 in handpiece 12 a must be overcome. During a typicaltreatment, the process of reorienting the tip must be carried outnumerous times. This is not only time consuming but also interrupts theease and smooth flow of work.

In areas of the mouth where the practitioner chooses not to rotate theinsert 14, the practitioner's wrist must be twisted sufficiently toachieve the same function. This twisting action is opposed by theresistance of the cable 12 b, the fluid supply hose and powerconductors, which is attached to the handpiece 12 a.

There continues to be a need for ultrasonic scalers which are morecomfortable and less fatiguing to use than known instruments.Preferably, any improvements will be downwardly compatible with thenumerous generators and handpieces that are already present in dentaloffices.

SUMMARY OF THE INVENTION

A rotatable ultrasonic insert has a body section which carries a bearingfor rotatably engaging an ultrasonic handpiece. The body is rotatable,about an axial centerline.

Rotation can be effected by applying a force only to the insert. Inresponse, the insert rotates but the handpiece does not. Hence, singlehanded, two finger rotation is possible.

Preferably, a swivel feature is located at the gripping region of theinsert, i.e., close to the treatment tip, where the practitioner wouldtypically position his or her fingers. The swivel allows the insert torotate 360 degrees without any limitation. This enables the practitionerto position the insert, and the tip, at any angular orientation withouthaving to take the insert out of the patient's mouth. The swivel alsoallows rotation of the gripping region and tip without having to rotatethe handpiece and/or the supply cord. This removes the resistance fromthe operator's hand and reduces hand fatigue.

Additionally, a large diameter grip or handle, not only reduces fingerfatigue but also transmits a larger torque to the swivel feature for thesame amount of force.

An elastomeric handle, carried by the body, comfortably interfaces witha user's fingers. The user can rotate the elastomeric handle and theinsert with two fingers relative to the handpiece. Hence, duringtreatment there will be no need to rotate the handpiece.

The elastomeric material allows for a positive grip since it deformsunder finger pressure and becomes locally non-cylindrical in shape. Thepreferred material is silicone. Silicone is not only repeatedlysterilizable under most sterilization processes found in dental officesbut also provides good traction with respect to the type of gloves whichare commonly used in dental offices.

The elastomeric handle engages the body only at a region of minimalultrasonically induced, vibration. The limited connectivity between thebody and the elastomeric handle minimizes build up of heat between thebody and that handle. It also avoids damping ultrasonic vibrationstransmitted along the body.

A method of assembly includes:

providing a body which carries an ultrasonic transducer, at one end,and, a displaced treatment applying tip at the other end;

sliding a rotary handle past the treatment applying tip toward thebearing;

connecting the handle to the body at a region of minimal ultrasonicvibration.

In another aspect of the invention, an adaptor has an external peripherywhich can be slidably and releasibly inserted into the opening in thehandpiece. A standard ultrasonic insert is inserted through the adaptorinto the handpiece. The insert can then be rotated relative to thehandpiece with a rotational force applied only thereto. Alternatively,the adaptor can be snap fitted onto an exterior periphery of ahandpiece.

Numerous other advantages and features of the present invention willbecome readily apparent from the following detailed description of theinvention and the embodiments thereof, from the claims and from theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a prior art ultrasonic scaler having an insert andhandpiece;

FIG. 1B illustrates one aspect of usage of the prior artinsert/handpiece combination of FIG. 1A;

FIG. 2A illustrates an insert in accordance with the present invention;

FIG. 2B illustrates the insert of FIG. 2A in a handpiece as in FIG. 1Aand aspects of usage thereof;

FIGS. 3A, B and C are various views of an ultrasonic insert body inaccordance with the present invention;

FIGS. 4A, B, C and D are various views of a snap-fit rotary bearingusable with the body of FIG. 3A;

FIGS. 5A, B, C and D are various views of a torque lock in accordancewith the present invention;

FIGS. 6A, B and C are various views of a swivel housing in accordancewith the present invention;

FIGS. 7A, B are various views of a cone usable in an insert inaccordance with the present invention;

FIGS. 8A, B and C illustrate steps in assembling an insert in accordancewith the present invention;

FIG. 9A is a side sectional view of an insert in accordance with theinvention illustrating the relationship of various elements assembled inthe steps of FIGS. 8A, B and C;

FIG. 9B is an enlarged sectional view illustrating aspects of a sectionof FIG. 9A;

FIG. 10A is a side sectional view of a handpiece carrying a snap-onadaptor in accordance with the present invention;

FIG. 10B is an enlarged partial side view of the handpiece and adaptorof FIG. 10A with a conventional ultrasonic insert positioned therein;

FIG. 10C is an over-all view of an insert as in FIG. 1 combined with anadaptor as in FIG. 10A;

FIG. 11A is an enlarged side view of an alternate embodiment of aninsert in accordance with the present invention;

FIG. 11B is an enlarged partial side sectional view of the insert ofFIG. 11A inserted into a handpiece of an ultrasonic scaling unit,generally of a type illustrated in FIG. 1;

FIG. 11C is a side view of a portion of the handpiece of FIG. 11B;

FIG. 11D is a side view of a collar threadable onto the handpiece ofFIG. 11B;

FIGS. 12A, B are top and side views of a preferred form of an ultrasonictransducer; and

FIG. 12C is an end view of the transducer of FIG. 12B.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

While this invention is susceptible of embodiment in many differentforms, there are shown in the drawing and will be described herein indetail specific embodiments thereof with the understanding that thepresent disclosure is to be considered as an exemplification of theprinciples of the invention and is not intended to limit the inventionto the specific embodiments illustrated.

FIG. 2A illustrates an insert 20 in accordance with the presentinvention. The insert 20 includes a transducer 20 a which is illustratedas a magnetostrictive transducer. Alternately, it could be apiezoelectric ultrasonic transducer without departing from the spiritand scope of the present invention.

The transducer is rigidly coupled to an elongated body 20 b which iscovered in part by a cylindrical, elongated deformable elastomeric grip20 c. The grip 20 c terminates in a cone 20 d which is positionedbetween the grip 20 c and operative treatment applying tip 20 e.

The insert 20 operates in accordance with the principals of knownultrasonic dental instruments as discussed above relative to FIG. 1A.However, insert 20 also carries a rotary bearing 24 which exhibits ahollow cylindrical stem section 24 a which defines a cylindrical region24 b which receives a sealing O-ring 24 c. The hollow member 24 aterminates at a disc 24 d of larger diameter. A planar surface 24 d-1 ofdisk 24 is adjacent to stem 24 a.

As discussed subsequently, when installed on the elongated body 20 b,the rotary bearing member 24 is rotatable relative to the body 20 b,gripping member 20 c and tip 20 e. Hence, if the member 24 is fixed, thebody 20 b, gripping member 20 c and tip 20 e are readily rotatabletherein.

FIG. 2B illustrates the standard ultrasonic handpiece 12 a, cable 12 band generator 12 c, discussed above, of a type found in dental offices.The insert 20 is slidably receivable, in a direction 16 a, in the hollowend 12 a-2 of the handpiece 12 a.

The cylindrical stem 24 a of the rotary bearing 24 slides into thehollow handpiece 12 a. The O-ring 24 c slidably engages the interiorperiphery of the handpiece 12 a providing a fluid seal and reliablyengaging the insert 20 with the handpiece 12 a.

When installed in the handpiece 12 a, as illustrated in FIG. 2B, insert20 can be rotated relative to handpiece 12 a with rotary forces appliedto the deformable gripping member 20 c for purposes of orienting the tip20 e relative to a tooth being deplaqued. As illustrated in FIG. 2B, thepractitioner need not restrain the handpiece 12 a while rotating theinsert 20. Additionally, insert 20 is relatively rotatable relative tohandpiece 12 a using only two of the practitioner's fingers. Thus, theorientation of the tip 20 e can be continuously altered with only two ofthe practitioner's fingers, requiring only one hand, while the scalingoperation proceeds. This will reduce operator fatigue and substantiallyshorten the time necessary for the scaling process. The expected torqueneeded to rotate insert 20 preferably will be less than 2.0 inch-oz.

When the practitioner has concluded the de-plaqueing process, the insert20 can be removed from the handpiece by pulling it axially from thehandpiece in a direction 16 b and sterilized. The same insert or adifferent insert can then be subsequently inserted into handpiece 12 ato treat the next patient. It will be understood that the presentinvention is applicable to ultrasonic inserts which utilize eithermagnetostrictive or piezoelectric transducers without limitation.

FIGS. 3A, 3B, 3C illustrate different views of the body 20 b of theinsert 20. As illustrated in FIGS. 3A and 3B, body portion 20 b isattached to a first end 20 a-1 of transducer 20 a as would be understoodby those of skill in the art. An elongated cylindrical extension 20 b-1extends axially from transducer 20 a toward tip 20 e.

The elongated cylindrical metal member 20 b-1, as would be known tothose of skill in the art, is caused to vibrate axially, in response toelectro-magnetic signals received at transducer 20 a from handpiece 12a. The signals are produced by generator 12 c. This axial ultrasonicvibration is in turn coupled to the tip 20 e and used for effectingde-plaqueing of the subject tooth T, in a spray of fluid M, illustratedin phantom in FIG. 3C.

A pair of notches 20 b-2, 20 b-3 is formed on elongated body member 20b-1 in a region of substantially zero axial ultrasonic vibration. Whilea pair of notches 20 b-2, -3 has been illustrated in FIG. 3B, it will beunderstood that a single notch, or three notches could be used withoutdeparting from the spirit and scope of the present invention.Additionally, the exact shape of the generally rectangular notches 20b-2, -3 is not a limitation of the present invention.

An interior or base plane 20 b-2′, 20 b-3′ of each notch 20 b-2, -3 isparallel to a plane through the central axis of tip 20 e. This notch/tipconfiguration facilitates energy transmission along insert 20 withoutincreasing the risk of a mechanical fracture due to potential fatiguestress.

An elongated fluid flow slot 20 b-4 extends axially in the region wherethe body 20 b-1 interfaces with the tip 20 e. As discussed subsequently,fluid for the spray M flows therethrough.

FIGS. 4A, B, C and D illustrate different views and additional detailsof rotary bearing 24. As illustrated therein, the cylindrical stem 24 ais hollow and defines an interior peripheral surface 24 e which isadjacent to the elongated body portion 20 b, see FIG. 2A. The bearingmember 24 carries a second O-ring 24 c-1 in a cylindrical region 24 d-2which is adjacent to a plurality of radially disposed spring-loadedfingers indicated generally at 24 g.

The fingers 24 g each terminate at a barbed free end, such as 24 g-1,-2, -3 with preferably four such fingers disposed radially about theannular surface 24 d-2. Neither the number nor the exact shape of theends 24 g-1, -2 . . . -n are limitations of the present invention. Asdiscussed in more detail subsequently, the fingers 24 g-1, -2, -3, -4are deflectable radially inward during assembly and are biased radiallyoutwardly to return to their undeflected condition, illustrated in FIGS.4A, 4B.

The second O-ring 24 c-1 which is positioned adjacent annular surface 24d-2 cooperates with O-ring 24 c to provide a sealed fluid flow pathbetween handpiece 12 a and cone 20 d. Cooling fluid flows from handpiece12 a through aperture 24-1, FIG. 4c, and past the fingers 24 g-1, -2,-3, -4. It will be understood that the number of fingers 24 g is not alimitation of the present invention.

FIGS. 5A-5D illustrate various views of a torque lock 30 which couples atorque due to force applied to deformable gripping member 20 c by theuser's fingers to the body 20 b and treatment tip 20 e. The torque lock30 is preferably molded of a sterilizable thermoplastic which, asdiscussed below, permits it to deform during assembly withoutfracturing.

The torque lock 30 has a hollow body section 32 a with an exteriorperiphery 32 b and an internal circumferential periphery 32 c. Thetorque lock is molded with a slot 34 a formed in the body 32 a whichpermits outward radial deformation of sections 34 b and 34 c, adjacentthe slot 34 a, as the torque lock 30 is slid onto the elongated bodyportion 20 b-1. Surfaces 36 a, 36 b slidably engage the notches 20 b-2,-3 of the elongated member 20 b-1. When the notches are so-engaged, thedeformable members 34 b, c move radially inwardly to a non-deformedcondition. In this state, torque lock 30 is locked to the body 20 b atthe notches 20 b-2, -3.

The interaction between the surfaces 36 a, b, in the slots 20 b-2, -3inhibits both rotation and translation of the torque lock 30 relative tothe body member 20 b-1. Hence, rotating the torque lock 30 will alsorotate the body 20 b of the insert.

Once the torque lock 30 has been installed on the body member 20 b-1 atthe slots 20 b-2, -3, it will be fixedly located at a region ofsubstantially zero axial ultrasonic vibration. This minimizes a build-upof heat between the vibrating body 20 b-1 and the torque lock 30. Aswill be understood by those of skill in the art, in addition to locatingthe notches 20 b-2, -3 at a region of minimal axial ultrasonicvibration, preferably centered on the expected nodal point of zerovibration, the cross section of the connecting body portion 20 b-1through the notches 20 b-2, -3 will have a large enough cross-sectionalarea to transmit ultrasonic vibrations without constriction.

FIGS. 6A, B, C illustrate various views of a housing 40 which is pressfit over torque lock 30 and which slidably and lockingly engages barbedfingers 24 g-1, -2, -3, and -4 of the rotary bearing 24. The housing 40has an elongated generally cylindrical body 42 a with a smooth exteriorperiphery 42 b. The body 42 a terminates at an end 42 c adjacent anannular shoulder 42 d.

The shoulder 42 d in turn has an end surface 42 d-1. When installed, theend surface 42 d-1 is adjacent to and rotates relative to annularsurface 24 d-3 of bearing 24.

The annular member 42 d exhibits an internal cylindrical peripheralsurface 42 d-2 which traps O-ring 24 c-1 in position, forming a fluidseal with bearing 24 when surface 42 d-1 is positioned adjacent tosurface 24 d-3. When so-positioned, the housing 40 can rotate relativeto bearing 24 but is not movable axially relative thereto.

When the housing 40 is rotated relative to the bearing 24, the surface42 d-2 slides over O-ring 24 c-1 without excessive friction therebyenabling a practitioner to rotate the tip 20 e relative to the handpiece12 a with the use of force applied to elastomeric gripping member 20 cby only two fingers.

The housing 40 has an interior, cylindrical peripheral surface 42 b-1which surface deflects the barbed fingers 24 g-1, -2, -3, -4 radiallyinwardly when the housing 40 is slid onto the fingers 24 g. The fingers24 g, which have been inwardly radially deflected by the surface 42 b-1engage a cylindrical slot 42 b-2 with a snap fit. The radiallycompressed fingers 24 g expand outwardly radially and the barbed ends 24g-1, -2, -3, -4 lock into the slot 42 b-2 precluding axial motion of thehousing 40 away from surface 24 d-3 of bearing 24.

As the housing 40 is slidably engaging the barbed fingers 24 g-1, -2,-3, -4 and internal cylindrical peripheral surface 42 b-3 engagesexterior cylindrical peripheral surface 32 b of torque lock 30 with apress or interference fit. The press fit between torque lock 30 andhousing 40 locks those two parts together precluding either axial linearmovement or rotary movement therebetween. The end 42 b of housing 40carries a plurality of threads 42 b-4.

The snap fit between the housing 40 and the rotary bearing 24, incombination with the O-ring 24 c-1 provide a sealed fluid flow path frominflow periphery 24 e of bearing 24 through outflow end surface 42 b-5of housing 40. This fluid flow seal, as noted above, precludes fluidleakage. The exterior cylindrical surface 24 g′ of each of the fingers24 g rotatably engages the internal cylindrical surface 42 b-1 of thehousing 40. This provides a pair of rotatable bearing surfaces whichpermit smooth two finger rotation of the deformable member 20 c and thetreatment tip 20 e. A medically acceptable, sterilizable, lubricant ispreferably provided between the bearing surfaces to improve rotationalsmoothness and further reduce friction and required torque.

FIGS. 7A and 7B are views of cone 20 d which is carried by rotatablehousing 40. Cone 20 d has an internal flow path 50 a which is sealed byO-ring 50 b. Cone 20 d includes a set of threads 52. Cone 20 d iscoupled to housing 40 by the rotatable engagement of threads 42 b-4 ofhousing 40 and 52 of cone 20 d.

The O-ring 50 b precludes leakage between an end 50 c and a region ofbody portion 20 b-1 which extends therethrough. Fluid exits cone 20 dvia fluid flow channel 20 b-4 in the body portion 20 b- 1. Fluid exitsthe cone 20 d in the channel 20 b-4 as a stream. The stream of fluidimpacts the vibrating tip 20 e and creates a smooth spray pattern Msuited for cooling and cleaning tissues. Adhesives, such as epoxy, canbe used to permanently attach the cone 20 d to the housing 40.

FIGS. 8A, 8B and 8C illustrate the steps of assembly of the insert 20.Groove 20 b′-1 in body section 20 b′ provides a positive grippingsurface usable during assembly by manufacturing fixtures to block axialmovement of the insert 20.

As illustrated in FIG. 8A, initial steps of assembly of the insert 20include sliding rotary bearing member 24 past operative tip 20 e ontobody portion 20 b-1. The torque lock 30 is then slid onto the operativeelement 20 e and forced along the elongated body 20 b-1, which in turnforces elements 34 b, c radially outward until surfaces 36 a, b thereofslidably engage the slots 20 b-2, -3. This slidable engagement with theslots in the body member 20 b locks the torque lock 30 to the bodymember 20 b and traps the bearing member 24 against a portion 20 b′ ofthe body 20 b precluding axial movement thereof. The bearing member 24continues to be rotatable relative to the elongated body portion 20 b.

As illustrated in FIG. 8B, the housing 40 is then slid onto and past theoperative element 20 e and forced onto the rotary bearing 24, therebyradially inwardly deflecting the barbed fingers 24 g-1, -2, -3, -4 andalso press fit onto external peripheral surface 32 b of torque lock 30adjacent to disc 24 d. When seated on the bearing member 24, theinwardly deflected fingers 24 g expand into radial slot 42 b-2, axiallylocking the housing 40 to the bearing 24 while still permitting relativerotary motion therebetween.

The circular elastomeric gripping member 20 c can be slid onto housing40 either before or after the cone 20 d is threadably engaged therewith.The gripping region 20 c has an inner diameter which is slightly smallerthan the outer diameter of the housing 40. The member 20 c thuselastically attempts to contract around the housing 40 which minimizesunintended slippage of the grip 20 c relative to the housing 40. Member20 c can also be permanently attached to housing 40 with adhesive.

FIG. 9A illustrates a side sectional view of an assembled insert 20 inaccordance with the method of steps of FIGS. 8A, B and C. FIG. 9B is anenlarged side sectional view of a portion of FIG. 9A furtherillustrating the relationships of the various elements therein.

As will be understood by those of skill in the art, preferably tip 20 cwill be formed and heat treated prior to the start of the assemblyprocess illustrated in FIG. 8A. By forming housing 40 as a separateelement from core 20 d, the length of each is less than the combinedlength of 20 d and 40. Hence, each can be independently slid overexemplary curved tip 20 e though the assembled combination 20 d and 40will not slide over tip 20 e.

FIG. 10A illustrates a snap-on plastic adaptor 70 which is intended tobe used with a standard handpiece, such as the handpiece 12 a. Asillustrated in FIG. 10A, handpiece 12 a includes an annular depression12 c adjacent to open end 12 a-2. The adaptor 70 snap-fits onto thehandpiece 12 a at the groove 12 c.

Adaptor 70 has a body section 72 a which carries an annular lockingprotrusion 72 b which slidably engages the slot 12 c locking the adaptor70 thereto. The adaptor 70 also includes a bearing 74 a which is carriedin an interior region 74 b of the body 72 a. An O-ring seal 74 c can bepositioned adjacent to the bearing 74 a to minimize the likelihood ofleakage from fluid flowing through the handpiece 12 a into an insertcoupled thereto.

The insert 70 defines a channel 76 a which co-extends with and abutschannel 12 d in handpiece 12 a. The channels 76 a and 12 d receive astandard insert such as the insert 14, which is to be rotatably coupledto handpiece 12 a and to be energized thereby.

FIG. 10B illustrates added details of standard insert 14 coupled toadaptor 70 for rotation relative to handpiece 12 a. In the embodimentillustrated in FIG. 10B, the adaptor 70 in combination with handpiece 12a and insert 14 provide a sealed fluid flow path between the interiorperipheral surface 12 b of the handpiece and tip 14 b of the insert. Inthis configuration, a user can rotate insert 14 relative to handpiece 12a by applying rotary forces to the grip 14 c in a manner analogous tothe way in which rotary forces are applied to the grip 20 c of rotatableinsert 20 previously described.

Using insert 70, a standard handpiece, in combination with standardinserts, such as the insert 14, can cost effectively provide improvedconvenience and comfort for the practitioner. It will be understood, ifdesired, that the insert 70 could be color coded. The insert 70 can bemolded of any sterilizable plastic such a thermoplastic materialcommercially available and known as polyphenylsulfone. It will also beunderstood that a plurality of snap-fit fingers, such as the fingers 72b, can be molded in housing 72 a for purposes of releasibly attachingthe adaptor to the handpiece 12 a.

FIG. 10C is an over-all view of insert 14 coupled to handpiece 12 a viaadaptor 70.

FIGS. 11A and 11B illustrate an alternate form of an adaptor 80 usablewith a handpiece 82. The adaptor 80 includes a cylindrical body section80 a which carries a bearing 80 b which could be implemented as aplastic ring bearing. The bearing 80 b is carried in a cylindrical slot80 c in housing 80 a.

Housing 80 a also carries an O-ring seal 80 d in a second slot 80 e.Finally, the body 80 a terminates at a plurality of deflectable lockingfingers 80 f. The body 80 a is hollow and defines an internal peripheralcylindrical surface 80 g.

Insert 80 is slidably receivable into handpiece 82 with a snap-fit. Theexterior surfaces of the fingers 80 f slidably engage a locking slot 82a formed in an interior peripheral surface 82 b of the handpiece 82. Theinterior peripheral surface 82 b also includes a slot 82 c for receiptof the O-ring seal 80 e, and, a slot 82 d which receives the rotarybearing 80 b carried by the insert 80. It will be understood that theO-ring 80 d provides a fluid seal between handpiece 82 and an insert,such as the insert 14 shown in part in phantom, which has been slidablyinserted into the adaptor 80 in contact with the internal peripheralcylindrical surface 80 g. When so-inserted, the insert 14 can berotated, along with adaptor 80 relative to the handpiece 82 so as topromote the convenience and comfort of a practitioner. A collar 86 isthreadable onto the end of the handpiece 82 to trap the adaptor 80 inplace and prevent axial movement thereof.

FIGS. 12A-C illustrate details of a preferred structure of stack 20 a.By impressing a “W” bend 20 a-1 along the length of each member of thestack, as illustrated, stiffness of the stack can be increased. This inturn promotes continued alignment of the stack relative to central axisHP-A, see FIG. 2B, while the insert 20 is being rotated. The improvedalignment minimizes the likelihood of the stack 20 a rubbing againstinternal peripheral surface 12 d during rotation, hence eliminating apossible source of friction and noise.

From the foregoing, it will be observed that numerous variations andmodifications may be effected without departing from the spirit andscope of the invention. It is to be understood that no limitation withrespect to the specific apparatus illustrated herein is intended orshould be inferred. It is, of course, intended to cover by the appendedclaims all such modifications as fall within the scope of the claims.

What is claimed:
 1. An ultrasonic insert which is engageable with ahollow handpiece, the insert comprising: a treatment applying tip; anultrasonic transducer coupled to the tip; a rotary bearing carriedbetween the transducer and the tip wherein the bearing is rotatablerelative to the tip and which includes an elongated member extendingbetween the tip and the transducer wherein the bearing is rotatablycarried on the member adjacent to a portion of the transducer.
 2. Aninsert as in claim 1 which includes a locking element which blocks thebearing from axial movement while permitting the rotary movement.
 3. Anultrasonic insert which is engageable with a hollow handpiece, theinsert comprising: a treatment applying tip; an ultrasonic transducercoupled to the tip; a rotary bearing carried between the transducer andthe tip wherein the bearing is rotatable relative to the tip, thebearing comprises a cylindrical sleeve rotatably carried adjacent to anend of the transducer; and which includes an elongated member extendingbetween the tip and the transducer wherein the bearing is rotatablycarried on the member adjacent to a portion of the transducer.
 4. Anultrasonic insert which is engageable with a hollow handpiece, theinsert comprising: a treatment applying tip; an ultrasonic transducercoupled to the tip; a rotary bearing carried between the transducer andthe tip wherein the bearing is rotatable relative to the tip, thebearing comprises a cylindrical sleeve rotatably carried adjacent to theend of the transducer; and wherein the sleeve includes an exteriorfeature slidably engageable with the handpiece.
 5. An insert as in claim4 wherein the exterior feature comprises an annular elastomeric member.6. A rotatable ultrasonic dental insert comprising: a treatment applyingtip, a transducer non-rotatably coupled to the tip and a handpieceengaging element, rotatably coupled to the tip, wherein the tip isrotatable relative to the engaging element by a force applied adjacentto the tip, and which carries a user comfortable, deformable,elastomeric member whereby the user can rotate the tip relative to theengaging element.
 7. An insert as in claim 6 which includes an elongatedbody with an end coupled to the tip and a torque transferring cylindercoupled between a portion of body and the elastomeric member whereby thecylinder is mechanically looked to the body such that a rotary forceapplied to the elastomeric member establishes a torque for rotating thebody.
 8. An insert as in claim 6 wherein the engaging element is coupledto the tip at a region of minimal axial ultrasonic vibration.
 9. Aninsert as in claim 8 wherein the engaging element includes a cylindricalbearing which is slidably lockable in a handpiece.
 10. An insert as inclaim 6 wherein the engaging element includes a rotary bearingpositioned adjacent to the elastomeric member whereby the tip andelastomeric member are rotatable together relative to a portion of theengaging element.
 11. An insert as in claim 10 wherein the bearing islocated at least in part, adjacent to a region of minimal axialultrasonic vibration.
 12. An insert as in claim 10 wherein the tip isrotatable through an arc on the order of at lest two hundred seventydegrees.
 13. A rotatable ultrasonic dental insert comprising: atreatment applying tip, and a transducer, the tip and transducer arenon-rotatably coupled together by an intervening coupling section, and ahandpiece engaging element, rotatably carried, at least in part, on thecoupling section, wherein the tip is rotatable relative to the engagingelement by a force applied adjacent to the tip, and which carries a usercomfortable, deformable, elastomeric member whereby the user can rotatethe tip relative to the engaging element.
 14. An insert as in claim 13which includes a cylinder coupled between a portion of coupling sectionand the elastomeric member whereby the cylinder is mechanically lockedto the coupling section such that a rotary force applied to theelastomeric member establishes a torque for rotating the tip.
 15. Aninsert as in claim 13 where the engaging element is located at least inpart, adjacent to a region of minimal axial ultrasonic vibration.
 16. Aninsert as in claim 13 where the tip is rotatable through an arc on theorder of at least two hundred seventy degrees.